Deciding for others alters metacognition, leading to responsibility aversion

People often need to take responsibility for others, with widespread and lasting impacts on both themselves and those affected by the choice outcomes. Responsibility for others has been shown to alter behaviour in decisions involving risk and ambiguity, and increase delegation rates. Our work demonstrates that the influence of responsibility extends beyond risky choices and acts at the metacognitive level. Responsibility for others changes metacognitive biases leading to a decrease in decision confidence. We propose and empirically test a normative computational framework based on decision confidence to explain delegation behaviours with social responsibility.